Update CHANGELOG.md to include #3702

CHANGELOG.md

@@ -7,8 +7,9 @@ FEATURES:
 
 IMPROVEMENTS:
 
-* `azurerm_app_service_plan` - prevent a panic during import [GH-3657]
 * `azurerm_app_service` - support for shipping the application logs to blob storage [GH-3520]
+* `azurerm_app_service_plan` - prevent a panic during import [GH-3657]
+* `azurerm_app_service_slot` - updating `identity` no longer forces a new resource [GH-3702]
 * `azurerm_key_vault_key` - add support for Elliptic Curve based keys [GH-1814]
 * `azurerm_traffic_manager_profile` - `ttl` can now be 1 second [GH-3632]
 * `azurerm_eventgrid_event_subscription` - now retrieves the full URL for event webhooks [GH-3630]